EXPLOSION SUPPRESSION
Combustible dust protection for collectors, silos, and process vessels.
IEP Technologies suppression, isolation, and venting, specified against your Kst and Pmax data and integrated with the collector rather than bolted on afterward.
Three ways to keep a deflagration from becoming a plant event.
A dust deflagration inside a collector is survivable equipment damage. The same event propagating back down the duct into the process is not. Protection gets specified as a system: detect and suppress the initial pressure rise, isolate the connected ductwork so the flame front cannot travel, and give the vessel a designed relief path.
ACTIVE SUPPRESSION
Detect the pressure rise, inject the suppressant.
Pressure and optical detectors see the deflagration in its first milliseconds and fire high-rate discharge bottles into the vessel, quenching the flame front before the vessel reaches its design pressure. Used on dust collectors, silos, and process vessels where venting to a safe outdoor location is not practical.
- Applied to dust collectors, silos, and industrial process vessels
- Bottle counts and placement follow the vessel volume and the measured Kst
- Suited to indoor equipment and to toxic or reactive dusts that cannot be vented to atmosphere
- Concept arrangements include one-bottle and three-bottle systems and backdraft configurations
ISOLATION
Stop the flame front at the duct.
Isolation is what keeps a collector event out of the building. Passive devices close on the pressure wave; active devices close on a signal from the detection system. Both are chosen from the dust class and the duct geometry.
- Proflap Plus III passive inlet duct isolation, applicable across a Kst 60 to 200 dust range
- High speed isolation valves rated to withstand pressure to 150 psig
- Chemical isolation barriers on inlet and outlet ducting
- Backdraft pinch valve arrangements available
VENTING
Relief panels and flameless venting.
Where the collector sits outdoors or against an exterior wall, a vent is usually the cheapest correct answer. Where it sits inside, a flameless vent quenches the flame and retains the burning material so the relief can stay indoors.
- Explosion vents in round, square, and rectangular formats
- Flat, domed, and insulated panel constructions
- Flameless vents for indoor equipment
- Magnetically activated burst sensors to signal a vent opening and shut the process down
Standards and testing
Protection is only defensible if it is tied to measured dust properties and a recognized standard. IEP equipment carries the approvals a plant safety officer and an insurer will ask for.
Design basis
- NFPA 69 for explosion prevention systems
- OSHA Combustible Dust National Emphasis Program
- ASTM E1226 for Kst and Pmax determination
Approvals
- FM Global approved equipment
- ATEX approved equipment
- Supported by the IEP Combustion Research Center
[NEEDS CLIENT INPUT: whether IWI performs dust hazard analyses in-house or refers them out, and which lab is used for Kst and Pmax sample testing]
[NEEDS CLIENT INPUT: NFPA 652 and NFPA 654 scope IWI is prepared to take responsibility for on a project]
Start with the dust data.
Send the material, the vessel volume, the duct runs, and any existing Kst report. If there is no report, that is the first line item.